Answers to practice problems

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Text (Notes) - Amanda Saravia and Gabby Sallada
Practice Problems - Cheyenne Stambaugh and Mary Sweitzer
Real-Life Applications- Devin Taylor
Multimedia - Alex schmitt


SECTION 6.1

Properties of Exponents


Name Of Property
Algebra
Example
*Product Of Powers*
a^m x a^n = a^m+n
2^3 x 2^4 = 27
Power Of A Power
(a^m)^n = a^mn
(2^4)^2 = 2^8
Power Of A Product
(ab)^m = a^m x b^m
( 3 x 4)^2 = 3^2 x 4^2
Negative Exponent
a^-m= 1/a^m
4^-2 = 1/4^2
Zero Exponent
a^0 = 1, a ≠ 0
4^0 = 1
*Quotient Of Powers*
a^m/a^n = a^m-n
5^2/5^1 = 5^1
Power Of A Quotient
(a/b)^m = (a^m/b^m)
(6/9)^2 = (6^2/9^2)
*Stars mean that bases need to be the same.*


Scientific Notation
A number expressed in the form c x 10^n where c is greater than or equal to one and less than ten and n is an integer.Example: .4500
4.5 x 10^3​



PRACTICE PROBLEMS
Evaluate the following expressions. Name the property that is used.
1. (2^3)^4
2. (3/4)^2
3. (-5)^-6(-5)^4
4. x^0
5. (7b^-3)^2b^5b


Word Problem:
An adult human body contains about 75,000,000,000,000 cells. Each cell is about 0.001 inch wide. If the cells were laid end to end to form a long chain, about how long would the chain be in miles? Give the answer in scientific notation.

Real-Life Applications- Properties of Exponents can be used to find the ratio of a state's park space to total area
Section 6.2
Polynomials-a sum of terms where each term is a constant times a whole number power of x.
Standard Form -when in standard form equation will have highest exponent of variable first and others will be in decreasing order.

Polynomials are classified by degrees.
Name----------------Degree-----------------Example
Constant-------------- 0 ---------------------- 4x^0=4(1)=4
Linear------------------ 1 ----------------------- 1/2x+3
Quadratic------------- 2 ----------------------- 4x^2+3x+2
Cubic------------------ 3 ---------------------- 5x^3+4x^2+x+3
Quartic---------------- 4 ----------------------- 8x^4+2x^3+x^2+x+3
Quintic---------------- 5 ----------------------- x^5-4

Leading coefficent is the number in front of a value with the greatest exponent
ex. -3x^4+1/2x^2-7 leading coefficent is -3

*Constant*=highest exoponent
*exponents must be positive integers*


*Polynomial functions
ex. f(x)= 5x+7 ex. f(x)= x^2+4x-7 ex. 3/2x^4-2/3x^2
*Not Polynomial functions
ex. f(x)= 2x+3/5x-2 ex. 2x^-3 ex. f(x)= 1/x^2-5x+3

-Monomial- 1 term
-Binomial- 2 terms
-Trinomial- 3 terms

Direct Substitution-when sustituting the x value in for x in order to sove the equation
Steps
1.) substitute x value in for x in the equation
2.) solve equation
ex.4x^4+3x^2+2x-1, x=4
4(4)^4=3(4)^2+2(4)-1
4(256)+3(16)+8-1
1024+48+7
1079

Synthetic Substitution-will be using coefficents and a given value for x
Steps
1.) write the value of x and the coefficents from the equation in decreasing order from left to right
2.) bring down the leading coefficent and multiply it by the x value

3.) write the answer in the next column and add the numbers in that column
4.) write the sum below the line and multiply it by the x value and put the product in the next colmn
5.) continue to add and multiply until the last coefficent has been added to a number and that gives you your answer
ex. 4x^4+3x^2+2x-1
4------0------3------2------(-1)

-----(16)---(64)--(268)--(1080)
(4)--(16)--(67)--(270)-(1079)
final answer: 1079
2-----0----(-8)-----5-----(-7)
-----(6)---(18)---(30)--(105)

2---(6)---(10)--(35)----(98)
final answer: 98




End Behavior of Polynomial Functions- end behavior of a polynomial function's graph is the behavior of a graph as x approches positive infinity(+oo) or negative infinity(-oo)
f(x) is y up to +oo(infinity) or down to -oo
x is positive +oo(right) or negative -oo(left)

ex. Put Graph here
ex. Put different graph, unlike first one,

Graphing Polynomials

1.) First, use a table of values to get started-> x I y
2.) Then,plug the different x values from the -3 I ?

table of values into the equation and put -2 I ?
the different answers into the table ofvalues. -1 I ?
3.) Lastly, plot the points from thetable of values 0 I ?
onto the graph 1 I ?

2 I ?

3 I ?

.

ex. PUT GRAPH HERE FOR EQUATIONS F(X)=4X+2 AND F(X)= -X^4-2X^3+2X^2+4X









Practice Problems for 6.2State whether or not the given function is a polynomial. If so, then state the degree, type, and leading coefficient.
1. f(x)= 12-5x
2. f(x)= x+π
3. f(x)= -2x^3-3x^-3+x
4. f(x)= x^2-x+1
5. f(x)= 3x^3

When x=5, evaluate the given polynomial functions using direct substitution.
1. f(x)= 2x^3+5x^2+4x+8
2. f(x)=x+1/2x^3
3. f(x)=5x^4-8x^3+7x^2
4. f(x)=11x^3-6x^2+2
5. f(x)=7x^3+9x^2+3x

When x=-3, evaluate the following fuctions using synthetic division.
1.f(x)= 3x^5+5x^3+2x+9
2. f(x)=x^2+1/2x-3
3. f(x)=x^4-6x^2+7x
4. f(x)=4x^3+x^2+2
5. f(x)=7x^4+5x^3+3x

Graph each function, then describe its end behavior.
1.-5x^3-2
2.x^2+1
3.x^5-2x^2+2



Real-Life Application- Evaluating and Graphing can be used in real life for example by finding out how much money is awarded at the U.S. open.
Combining Polynomials
Adding
Add like terms-varibles and exponents are the same----->ex. (3x^2+7+x)+(14x^3+2+x^2-X)=14x^3+4x^2+9-->Adding horizontially
-----------standard form-> 3x^2+x+2
adding vertically->+14x^3+x^2-x+2 answer------>14x^3+4x^2+9



Subtracting8x^3-3x^2-2x+9
-2x^3-6x^2+x-1
8x^3-3x^2-2x+9
-(2x^3+6x^2-x+1)<-----add the opposite
6x^3-9x^2-x+8


(2x^2+3x)-(3x^2+x-4)=2x^2+3x-3x^2-x+4=-x^2+2x+4



Multiplication
When you multiply, all you do is foil the problem out and then combine like terms and put in standard form.

ex. (4x - 5) (2x^5 + x^3 -1)
FOIL->8x^6 + 4x^4 - 4x - 10x^5 - 5x^3 + 5
8x^6 - 10x^5 + 4x^4 - 5x^3 - 4x +5


*Box Method*
(3x-4)(8x-1)
l 3x l -4
8x l 24x^2 l -32x

-1 l -3x l 4
then, add like terms and you get 24x^2-35x+4
*when multiplying any kind of 2 polynomials box method can be used*

Long Division
First put the problem into standard form. Then divide like you would divide a regular problem. If you are left with a remainder or not zero put that over the divisor.

2x_+_1_+_5 /x+4
x + 4 ) 2x^2 + 9x + 9
- 2x^2 - 8x
x +9
-x - 4
5

Synthetic Division

The number in the box should make the linear binomial equal zero. It is an intercept. The boxed number is a remainder. To do synthetic division you do the same as synthetic substitution.

ex. -3] 6 -5 -6
------------(-18 69
---------(6 -23 [63]

6x - 23 + 63 /x + 3


Real-Life Applications- Combining polynomials can be used in real life by seeing how much power is needed to keep a bike moving at a certain speed.
Theorems
Remainder Theorem - If a polynomial f(x) is divided by ( x - k ), then the remainder is f(k) = r.
In other words, when you divide using synthetic division, such as below, the remainder will bethe same as when you use direct substitution.
ex. ( 3x^2 + 5x - 2) / ( x + 4)

4] 3 5 -2
-12 28
3 -7 26

3(-4^2) + 5(-4) - 2
3(16) - 20 - 2
48 - 2 - 2
26


Factor Theorem- A polynomial f(x) has a factor ( x - k ) if and only if f(k) = 0.
ex. x^2-4
(x+2)(x-2)


-2] 1 0 -4
--------(-2 4
-----(1 -2
[0

2] 1 0 -4

-------(2 4
----(1 2
[0

-2 and 2 are the "zeros" of the polynomial. they also are the x intercepts

ex. 2x^3+5x^2-x+7 when x=2

2(2)^3+5(2)^2-2+7
32+20+5=41

2] 2 5 -1 7
-------(4 18 34
---(2 9 17 [41


Rational Zero Theorem- p/q = factor of constant term a0 / factor of leading coefficient

To find the zero use the p/q test to find all possible zeros. Then use synthetic division to see if one of the possible zeros is a zero. Next the equation you get from synthetic division needs to be factored. Once its factored you can solve for the rest of the zeros.

ex. f(x) = x^3 + 2x^2 - 11x - 12
p/q = +/- 1, 2, 3, 4, 6, 12
- 1 ] 1 2 -11 -12
-1 -1 12
1 1 -12 0
f(x) = (x +1) (x^2 + x - 12)
f(x) = (x + 1) ( x - 3) ( x + 4)
zeros are -1, 3, and -4



Fundamental Theorem - If f(x) is a polynomial of degree n where n > 0, then the equation f(x) = 0 has at least one root in the set of complex numbers.

Imaginary roots always come in pairs.

Real-Life Applications- In factoring and solving is finding the dimensions of a block discovered underwater.


Section 6.8

Let f(x) = anx^n + an - 1x^n-1 + ... + a1x + a0. The following statements are equivalent.
Zero - k is zero of the polynomial function f
Factor - x - k is a factor of the polynomial f(x)
Solution - k is a solution of the polynomial equation f(x) = 0.
If k is a real number, then the following is a also equivalent.
X intercept- k is an x-intercept of the graph of the polynomial function f.


Local Maximum - the y coordinate of a turning point that is higher than all nearby points.
Local Minimum - the y coordinate of a turning point that is lower than all nearby points.


Turning Points of Polynomial Functions
The graph of every polynomial function of degree n has at most n - 1 turning points. Moreover, if a polynomial function has n distinct real zeros, then its graph has exactly n - 1 turning points.




Practice Problems for 6.3:
#1.Find the sum or difference.
a.(-3x^3+x-11) - (4x^3+x^2-x)
b.(10x^3-4x^2+3x) - (x^3-x^2+1)
c.(10x-3+7x^2) + (x^3-2x+17)

#2. Multiply the polynomials.
a.x(x^2+6x-7)
b.-4x(x^2-8x+3)
c.(x-4)(x-7)

#3. Multiply the three binomials.
a.(x+9)(x-2)(x-7)
b.(x+5)(x+7)(-x+1)
c.(x-9)(x-2)(3x+2)**




Practice Problems for 6.4:
Factor the polynomial using any method.
1.x^6+125
2.X^4-1
3.5x^3-320
4.3x^2+11x+6
5.125x^3-216

Find the GCF
1.3x^4-12x^3
2.24x^4-x^6
3.145x^9-17

Factor.
1. x^3-8
2. 216x^3+1
3. 1000x^3+27

Factor by Grouping
1. x^3+x^2+x+1
2.x^3+3x^2+10x+30
3.2^3-5x^2+18x-45

Find the real number solutions.
1.2x^3-6x^2=0
2.x^3+27=0
3.x^4+7X^3-8x-56=0
4.3X^7-243x^3=0
5.8x^3-1=0

Real-Life Applications- In Factoring and Solving polynomial equations is finding the dimensions of a block discovered underwater


Practice Problems for 6.5:
#1. Use Synthetic Division.
a. Dividex^3+2x^2-6x-9 by x+3
b. Divide2x^4+3x^3+5x-1 by x-2
c. Divide 4x^3-x^2+5x-1 by x-4

#2.Find the factors of the polynomial given that f(k)=0.
a.f(x)=2x^3+11x^2+18x+9 k= -3
b.f(x)=x^3-5x^2-2x+24 k= -2
c.f(x)=4x^3-4x^2-9x+9 k=1

#3.Find the other zeros of the polynomial function.
a. One zero of f(x)=x^3-2x^2-9x+18 is x=2
b. One zero of f(x)=9x^3+10x^2-17x-2 is x= -2
c. One zero of f(x)=2x^3+3x^2-39x-20 is x=4

#4. Use polynomial long divison.
a.(x^2+7x-5) / (x-2)
b.(2x^2+3x-1) / (x+4)
c.(x^2+5x-3) / (x-10)
Real-Life Applications- In in the Remainder an Factor Theorems is used in finding a production level that yields a certain profit



Practice Problems for 6.6:
#1.Find all possible rational zeros.
a.f(x)=x^3+2x^2-11x-12
b.f(x)=x^4+2x^2-24
c.f(x)=2x^5+x^2+16

#2. Using sythetic divison decide which of the following are zeros of the function; 1, -1, 2, -2.
a.f(x)=x^3+7x^2-4x-28
b.f(x)=x^4+3x^3-7x^2-27x-18
c.f(x)=x^4+3x^3+3x^2-3x-4

#3.Find all the real zeros of the function.
a.f(x)=x^3-8x^2-23x+30
b.f(x)=x^3-7x^2+2x+40
c.f(x)=x^3+72-5x^2-18x
Real-Life Applications- In Finding Rational Zeros can be used to find the dimensions of a monument
6.7 Real-Life Applications- In Fundamental Theorem is used in real life by finding the population of certain people
Practice Problems for 6.8:
#1. Estimate the coordinates of each turning point and state whether each cooresponds to a local maximum or a local minimum. Then list all the real zeros and determine the least degree that the function can have.
book_page_376.jpg
do numbers 23, 25 and 27.

#2.Use a graphing calculator to graph the polynomial function. Identify the x-intercepts and the points where te local maximums and local minimums occur.
a.f(x)=3x^3-9x+1
b.f(x)= -1/4x^4+2x^2
c.f(x)=x^5-5x^3+4x

#3. Graph the function.
a.f(x)=(x-1)^3(x+1)
b.f(x)=1/8(x+4)(x+2)(x-3)
c.f(x)=5(x-1)(x-2)(x-3)

Real-Life Applications- In Analyzing graphs is used to find the certain crop productions in the United States